An admirable statement of the aims of the Library of Philosophywas provided by the first editor, the late Professor J. H.Muirhead, in his description of the original programme printed inErdmann's History of Philosophy under the date 1890. This wasslightly modified in subsequent volumes to take the form of thefollowing statement:

"The Muirhead Library of Philosophy was designed as acontribution to the History of Modern Philosophy under the heads:first of Different Schools of Thought--Sensationalist, Realist,Idealist, Intuitivist; secondly of differentSubjects--Psychology, Ethics, Aesthetics, Political Philosophy,Theology. While much had been done in England in tracing thecourse of evolution in nature, history, economics, morals andreligion, little had been done in tracing the development ofthought on these subjects. Yet 'the evolution of opinion is partof the whole evolution'.

"By the co-operation of different writers in carrying out thisplan it was hoped that a thoroughness and completeness oftreatment, otherwise unattainable, might be secured. It wasbelieved also that from writers mainly British and Americanfuller consideration of English Philosophy than it had hithertoreceived might be looked for. In the earlier series of bookscontaining, among others, Bosanquet's "History of Aesthetic,"Pfleiderer's "Rational Theology since Kant," Albee's "History ofEnglish Utilitarianism," Bonar's "Philosophy and PoliticalEconomy," Brett's "History of Psychology," Ritchie's "NaturalRights," these objects were to a large extent effected.

"In the meantime original work of a high order was being producedboth in England and America by such writers as Bradley, Stout,Bertrand Russell, Baldwin, Urban, Montague, and others, and a newinterest in foreign works, German, French and Italian, which hadeither become classical or were attracting public attention, haddeveloped. The scope of the Library thus became extended intosomething more international, and it is entering on the fifthdecade of its existence in the hope that it may contribute tothat mutual understanding between countries which is so pressinga need of the present time."

The need which Professor Muirhead stressed is no less pressingto-day, and few will deny that philosophy has much to do withenabling us to meet it, although no one, least of all Muirheadhimself, would regard that as the sole, or even the main, objectof philosophy. As Professor Muirhead continues to lend thedistinction of his name to the Library of Philosophy it seemednot inappropriate to allow him to recall us to these aims in hisown words. The emphasis on the history of thought also seemed tome very timely; and the number of important works promised forthe Library in the very near future augur well for the continuedfulfilment, in this and other ways, of the expectations of theoriginal editor.

H. D. Lewis

PREFACE

This book has grown out of an attempt to harmonize two differenttendencies, one in psychology, the other in physics, with both ofwhich I find myself in sympathy, although at first sight theymight seem inconsistent. On the one hand, many psychologists,especially those of the behaviourist school, tend to adopt whatis essentially a materialistic position, as a matter of method ifnot of metaphysics. They make psychology increasingly dependenton physiology and external observation, and tend to think ofmatter as something much more solid and indubitable than mind.Meanwhile the physicists, especially Einstein and other exponentsof the theory of relativity, have been making "matter" less andless material. Their world consists of "events," from which"matter" is derived by a logical construction. Whoever reads, forexample, Professor Eddington's "Space, Time and Gravitation"(Cambridge University Press, 1920), will see that anold-fashioned materialism can receive no support from modernphysics. I think that what has permanent value in the outlook ofthe behaviourists is the feeling that physics is the mostfundamental science at present in existence. But this positioncannot be called materialistic, if, as seems to be the case,physics does not assume the existence of matter.

The view that seems to me to reconcile the materialistic tendencyof psychology with the anti-materialistic tendency of physics isthe view of William James and the American new realists,according to which the "stuff" of the world is neither mental normaterial, but a "neutral stuff," out of which both areconstructed. I have endeavoured in this work to develop this viewin some detail as regards the phenomena with which psychology isconcerned.

My thanks are due to Professor John B. Watson and to Dr. T. P.Nunn for reading my MSS. at an early stage and helping me withmany valuable suggestions; also to Mr. A. Wohlgemuth for muchvery useful information as regards important literature. I havealso to acknowledge the help of the editor of this Library ofPhilosophy, Professor Muirhead, for several suggestions by whichI have profited.

The work has been given in the form of lectures both in Londonand Peking, and one lecture, that on Desire, has been publishedin the Athenaeum.

There are a few allusions to China in this book, all of whichwere written before I had been in China, and are not intended tobe taken by the reader as geographically accurate. I have used"China" merely as a synonym for "a distant country," when Iwanted illustrations of unfamiliar things.

There are certain occurrences which we are in the habit ofcalling "mental." Among these we may take as typical BELIEVINGand DESIRING. The exact definition of the word "mental" will, Ihope, emerge as the lectures proceed; for the present, I shallmean by it whatever occurrences would commonly be called mental.

I wish in these lectures to analyse as fully as I can what it isthat really takes place when we, e.g. believe or desire. In thisfirst lecture I shall be concerned to refute a theory which iswidely held, and which I formerly held myself: the theory thatthe essence of everything mental is a certain quite peculiarsomething called "consciousness," conceived either as a relationto objects, or as a pervading quality of psychical phenomena.

The reasons which I shall give against this theory will be mainlyderived from previous authors. There are two sorts of reasons,which will divide my lecture into two parts

(1) Direct reasons, derived from analysis and its difficulties;

(2) Indirect reasons, derived from observation of animals(comparative psychology) and of the insane and hysterical(psycho-analysis).

Few things are more firmly established in popular philosophy thanthe distinction between mind and matter. Those who are notprofessional metaphysicians are willing to confess that they donot know what mind actually is, or how matter is constituted; butthey remain convinced that there is an impassable gulf betweenthe two, and that both belong to what actually exists in theworld. Philosophers, on the other hand, have maintained oftenthat matter is a mere fiction imagined by mind, and sometimesthat mind is a mere property of a certain kind of matter. Thosewho maintain that mind is the reality and matter an evil dreamare called "idealists"--a word which has a different meaning inphilosophy from that which it bears in ordinary life. Those whoargue that matter is the reality and mind a mere property ofprotoplasm are called "materialists." They have been rare amongphilosophers, but common, at certain periods, among men ofscience. Idealists, materialists, and ordinary mortals have beenin agreement on one point: that they knew sufficiently what theymeant by the words "mind" and "matter" to be able to conducttheir debate intelligently. Yet it was just in this point, as towhich they were at one, that they seem to me to have been allalike in error.

The stuff of which the world of our experience is composed is, inmy belief, neither mind nor matter, but something more primitivethan either. Both mind and matter seem to be composite, and thestuff of which they are compounded lies in a sense between thetwo, in a sense above them both, like a common ancestor. Asregards matter, I have set forth my reasons for this view onformer occasions,* and I shall not now repeat them. But thequestion of mind is more difficult, and it is this question thatI propose to discuss in these lectures. A great deal of what Ishall have to say is not original; indeed, much recent work, invarious fields, has tended to show the necessity of such theoriesas those which I shall be advocating. Accordingly in this firstlecture I shall try to give a brief description of the systems ofideas within which our investigation is to be carried on.

If there is one thing that may be said, in the popularestimation, to characterize mind, that one thing is"consciousness." We say that we are "conscious" of what we seeand hear, of what we remember, and of our own thoughts andfeelings. Most of us believe that tables and chairs are not"conscious." We think that when we sit in a chair, we are awareof sitting in it, but it is not aware of being sat in. It cannotfor a moment be doubted that we are right in believing that thereis SOME difference between us and the chair in this respect: somuch may be taken as fact, and as a datum for our inquiry. But assoon as we try to say what exactly the difference is, we becomeinvolved in perplexities. Is "consciousness" ultimate and simple,something to be merely accepted and contemplated? Or is itsomething complex, perhaps consisting in our way of behaving inthe presence of objects, or, alternatively, in the existence inus of things called "ideas," having a certain relation toobjects, though different from them, and only symbolicallyrepresentative of them? Such questions are not easy to answer;but until they are answered we cannot profess to know what wemean by saying that we are possessed of "consciousness."

Before considering modern theories, let us look first atconsciousness from the standpoint of conventional psychology,since this embodies views which naturally occur when we begin toreflect upon the subject. For this purpose, let us as apreliminary consider different ways of being conscious.

First, there is the way of PERCEPTION. We "perceive" tables andchairs, horses and dogs, our friends, traffic passing in thestreet--in short, anything which we recognize through the senses.I leave on one side for the present the question whether puresensation is to be regarded as a form of consciousness: what I amspeaking of now is perception, where, according to conventionalpsychology, we go beyond the sensation to the "thing" which itrepresents. When you hear a donkey bray, you not only hear anoise, but realize that it comes from a donkey. When you see atable, you not only see a coloured surface, but realize that itis hard. The addition of these elements that go beyond crudesensation is said to constitute perception. We shall have more tosay about this at a later stage. For the moment, I am merelyconcerned to note that perception of objects is one of the mostobvious examples of what is called "consciousness." We are"conscious" of anything that we perceive.

We may take next the way of MEMORY. If I set to work to recallwhat I did this morning, that is a form of consciousnessdifferent from perception, since it is concerned with the past.There are various problems as to how we can be conscious now ofwhat no longer exists. These will be dealt with incidentally whenwe come to the analysis of memory.

From memory it is an easy step to what are called "ideas"--not inthe Platonic sense, but in that of Locke, Berkeley and Hume, inwhich they are opposed to "impressions." You may be conscious ofa friend either by seeing him or by "thinking" of him; and by"thought" you can be conscious of objects which cannot be seen,such as the human race, or physiology. "Thought" in the narrowersense is that form of consciousness which consists in "ideas" asopposed to impressions or mere memories.

We may end our preliminary catalogue with BELIEF, by which I meanthat way of being conscious which may be either true or false. Wesay that a man is "conscious of looking a fool," by which we meanthat he believes he looks a fool, and is not mistaken in thisbelief. This is a different form of consciousness from any of theearlier ones. It is the form which gives "knowledge" in thestrict sense, and also error. It is, at least apparently, morecomplex than our previous forms of consciousness; though we shallfind that they are not so separable from it as they might appearto be.

Besides ways of being conscious there are other things that wouldordinarily be called "mental," such as desire and pleasure andpain. These raise problems of their own, which we shall reach inLecture III. But the hardest problems are those that ariseconcerning ways of being "conscious." These ways, taken together,are called the "cognitive" elements in mind, and it is these thatwill occupy us most during the following lectures.

There is one element which SEEMS obviously in common among thedifferent ways of being conscious, and that is, that they are alldirected to OBJECTS. We are conscious "of" something. Theconsciousness, it seems, is one thing, and that of which we areconscious is another thing. Unless we are to acquiesce in theview that we can never be conscious of anything outside our ownminds, we must say that the object of consciousness need not bemental, though the consciousness must be. (I am speaking withinthe circle of conventional doctrines, not expressing my ownbeliefs.) This direction towards an object is commonly regardedas typical of every form of cognition, and sometimes of mentallife altogether. We may distinguish two different tendencies intraditional psychology. There are those who take mental phenomenanaively, just as they would physical phenomena. This school ofpsychologists tends not to emphasize the object. On the otherhand, there are those whose primary interest is in the apparentfact that we have KNOWLEDGE, that there is a world surrounding usof which we are aware. These men are interested in the mindbecause of its relation to the world, because knowledge, if it isa fact, is a very mysterious one. Their interest in psychology isnaturally centred in the relation of consciousness to its object,a problem which, properly, belongs rather to theory of knowledge.We may take as one of the best and most typical representativesof this school the Austrian psychologist Brentano, whose"Psychology from the Empirical Standpoint,"* though published in1874, is still influential and was the starting-point of a greatdeal of interesting work. He says (p. 115):

"Every psychical phenomenon is characterized by what thescholastics of the Middle Ages called the intentional (also themental) inexistence of an object, and what we, although with notquite unambiguous expressions, would call relation to a content,direction towards an object (which is not here to be understoodas a reality), or immanent objectivity. Each contains somethingin itself as an object, though not each in the same way. Inpresentation something is presented, in judgment something isacknowledged or rejected, in love something is loved, in hatredhated, in desire desired, and so on.

"This intentional inexistence is exclusively peculiar topsychical phenomena. No physical phenomenon shows anythingsimilar. And so we can define psychical phenomena by saying thatthey are phenomena which intentionally contain an object inthemselves."

The view here expressed, that relation to an object is anultimate irreducible characteristic of mental phenomena, is onewhich I shall be concerned to combat. Like Brentano, I aminterested in psychology, not so much for its own sake, as forthe light that it may throw on the problem of knowledge. Untilvery lately I believed, as he did, that mental phenomena haveessential reference to objects, except possibly in the case ofpleasure and pain. Now I no longer believe this, even in the caseof knowledge. I shall try to make my reasons for this rejectionclear as we proceed. It must be evident at first glance that theanalysis of knowledge is rendered more difficult by therejection; but the apparent simplicity of Brentano's view ofknowledge will be found, if I am not mistaken, incapable ofmaintaining itself either against an analytic scrutiny or againsta host of facts in psycho-analysis and animal psychology. I donot wish to minimize the problems. I will merely observe, inmitigation of our prospective labours, that thinking, however itis to be analysed, is in itself a delightful occupation, and thatthere is no enemy to thinking so deadly as a false simplicity.Travelling, whether in the mental or the physical world, is ajoy, and it is good to know that, in the mental world at least,there are vast countries still very imperfectly explored.

The view expressed by Brentano has been held very generally, anddeveloped by many writers. Among these we may take as an examplehis Austrian successor Meinong.* According to him there are threeelements involved in the thought of an object. These three hecalls the act, the content and the object. The act is the same inany two cases of the same kind of consciousness; for instance, ifI think of Smith or think of Brown, the act of thinking, initself, is exactly similar on both occasions. But the content ofmy thought, the particular event that is happening in my mind, isdifferent when I think of Smith and when I think of Brown. Thecontent, Meinong argues, must not be confounded with the object,since the content must exist in my mind at the moment when I havethe thought, whereas the object need not do so. The object may besomething past or future; it may be physical, not mental; it maybe something abstract, like equality for example; it may besomething imaginary, like a golden mountain; or it may even besomething self-contradictory, like a round square. But in allthese cases, so he contends, the content exists when the thoughtexists, and is what distinguishes it, as an occurrence, fromother thoughts.

To make this theory concrete, let us suppose that you arethinking of St. Paul's. Then, according to Meinong, we have todistinguish three elements which are necessarily combined inconstituting the one thought. First, there is the act ofthinking, which would be just the same whatever you were thinkingabout. Then there is what makes the character of the thought ascontrasted with other thoughts; this is the content. And finallythere is St. Paul's, which is the object of your thought. Theremust be a difference between the content of a thought and what itis about, since the thought is here and now, whereas what it isabout may not be; hence it is clear that the thought is notidentical with St. Paul's. This seems to show that we mustdistinguish between content and object. But if Meinong is right,there can be no thought without an object: the connection of thetwo is essential. The object might exist without the thought, butnot the thought without the object: the three elements of act,content and object are all required to constitute the one singleoccurrence called "thinking of St. Paul's."

The above analysis of a thought, though I believe it to bemistaken, is very useful as affording a schema in terms of whichother theories can be stated. In the remainder of the presentlecture I shall state in outline the view which I advocate, andshow how various other views out of which mine has grown resultfrom modifications of the threefold analysis into act, contentand object.

The first criticism I have to make is that the ACT seemsunnecessary and fictitious. The occurrence of the content of athought constitutes the occurrence of the thought. Empirically, Icannot discover anything corresponding to the supposed act; andtheoretically I cannot see that it is indispensable. We say: "_I_think so-and-so," and this word "I" suggests that thinking is theact of a person. Meinong's "act" is the ghost of the subject, orwhat once was the full-blooded soul. It is supposed that thoughtscannot just come and go, but need a person to think them. Now, ofcourse it is true that thoughts can be collected into bundles, sothat one bundle is my thoughts, another is your thoughts, and athird is the thoughts of Mr. Jones. But I think the person is notan ingredient in the single thought: he is rather constituted byrelations of the thoughts to each other and to the body. This isa large question, which need not, in its entirety, concern us atpresent. All that I am concerned with for the moment is that thegrammatical forms "I think," "you think," and "Mr. Jones thinks,"are misleading if regarded as indicating an analysis of a singlethought. It would be better to say "it thinks in me," like "itrains here"; or better still, "there is a thought in me." This issimply on the ground that what Meinong calls the act in thinkingis not empirically discoverable, or logically deducible from whatwe can observe.

The next point of criticism concerns the relation of content andobject. The reference of thoughts to objects is not, I believe,the simple direct essential thing that Brentano and Meinongrepresent it as being. It seems to me to be derivative, and toconsist largely in BELIEFS: beliefs that what constitutes thethought is connected with various other elements which togethermake up the object. You have, say, an image of St. Paul's, ormerely the word "St. Paul's" in your head. You believe, howevervaguely and dimly, that this is connected with what you would seeif you went to St. Paul's, or what you would feel if you touchedits walls; it is further connected with what other people see andfeel, with services and the Dean and Chapter and Sir ChristopherWren. These things are not mere thoughts of yours, but yourthought stands in a relation to them of which you are more orless aware. The awareness of this relation is a further thought,and constitutes your feeling that the original thought had an"object." But in pure imagination you can get very similarthoughts without these accompanying beliefs; and in this caseyour thoughts do not have objects or seem to have them. Thus insuch instances you have content without object. On the otherhand, in seeing or hearing it would be less misleading to saythat you have object without content, since what you see or hearis actually part of the physical world, though not matter in thesense of physics. Thus the whole question of the relation ofmental occurrences to objects grows very complicated, and cannotbe settled by regarding reference to objects as of the essence ofthoughts. All the above remarks are merely preliminary, and willbe expanded later.

Speaking in popular and unphilosophical terms, we may say thatthe content of a thought is supposed to be something in your headwhen you think the thought, while the object is usually somethingin the outer world. It is held that knowledge of the outer worldis constituted by the relation to the object, while the fact thatknowledge is different from what it knows is due to the fact thatknowledge comes by way of contents. We can begin to state thedifference between realism and idealism in terms of thisopposition of contents and objects. Speaking quite roughly andapproximately, we may say that idealism tends to suppress theobject, while realism tends to suppress the content. Idealism,accordingly, says that nothing can be known except thoughts, andall the reality that we know is mental; while realism maintainsthat we know objects directly, in sensation certainly, andperhaps also in memory and thought. Idealism does not say thatnothing can be known beyond the present thought, but it maintainsthat the context of vague belief, which we spoke of in connectionwith the thought of St. Paul's, only takes you to other thoughts,never to anything radically different from thoughts. Thedifficulty of this view is in regard to sensation, where it seemsas if we came into direct contact with the outer world. But theBerkeleian way of meeting this difficulty is so familiar that Ineed not enlarge upon it now. I shall return to it in a laterlecture, and will only observe, for the present, that there seemto me no valid grounds for regarding what we see and hear as notpart of the physical world.

Realists, on the other hand, as a rule, suppress the content, andmaintain that a thought consists either of act and object alone,or of object alone. I have been in the past a realist, and Iremain a realist as regards sensation, but not as regards memoryor thought. I will try to explain what seem to me to be thereasons for and against various kinds of realism.

Modern idealism professes to be by no means confined to thepresent thought or the present thinker in regard to itsknowledge; indeed, it contends that the world is so organic, sodove-tailed, that from any one portion the whole can be inferred,as the complete skeleton of an extinct animal can be inferredfrom one bone. But the logic by which this supposed organicnature of the world is nominally demonstrated appears torealists, as it does to me, to be faulty. They argue that, if wecannot know the physical world directly, we cannot really knowany thing outside our own minds: the rest of the world may bemerely our dream. This is a dreary view, and they there fore seekways of escaping from it. Accordingly they maintain that inknowledge we are in direct contact with objects, which may be,and usually are, outside our own minds. No doubt they areprompted to this view, in the first place, by bias, namely, bythe desire to think that they can know of the existence of aworld outside themselves. But we have to consider, not what ledthem to desire the view, but whether their arguments for it arevalid.

There are two different kinds of realism, according as we make athought consist of act and object, or of object alone. Theirdifficulties are different, but neither seems tenable allthrough. Take, for the sake of definiteness, the remembering of apast event. The remembering occurs now, and is thereforenecessarily not identical with the past event. So long as weretain the act, this need cause no difficulty. The act ofremembering occurs now, and has on this view a certain essentialrelation to the past event which it remembers. There is noLOGICAL objection to this theory, but there is the objection,which we spoke of earlier, that the act seems mythical, and isnot to be found by observation. If, on the other hand, we try toconstitute memory without the act, we are driven to a content,since we must have something that happens NOW, as opposed to theevent which happened in the past. Thus, when we reject the act,which I think we must, we are driven to a theory of memory whichis more akin to idealism. These arguments, however, do not applyto sensation. It is especially sensation, I think, which isconsidered by those realists who retain only the object.* Theirviews, which are chiefly held in America, are in large measurederived from William James, and before going further it will bewell to consider the revolutionary doctrine which he advocated. Ibelieve this doctrine contains important new truth, and what Ishall have to say will be in a considerable measure inspired byit.

* This is explicitly the case with Mach's "Analysis ofSensations," a book of fundamental importance in the presentconnection. (Translation of fifth German edition, Open Court Co.,1914. First German edition, 1886.)

William James's view was first set forth in an essay called "Does'consciousness' exist?"* In this essay he explains how what usedto be the soul has gradually been refined down to the"transcendental ego," which, he says, "attenuates itself to athoroughly ghostly condition, being only a name for the fact thatthe 'content' of experience IS KNOWN. It loses personal form andactivity--these passing over to the content--and becomes a bareBewusstheit or Bewusstsein uberhaupt, of which in its own rightabsolutely nothing can be said. I believe (he continues) that'consciousness,' when once it has evaporated to this estate ofpure diaphaneity, is on the point of disappearing altogether. Itis the name of a nonentity, and has no right to a place amongfirst principles. Those who still cling to it are clinging to amere echo, the faint rumour left behind by the disappearing'soul' upon the air of philosophy"(p. 2).

He explains that this is no sudden change in his opinions. "Fortwenty years past," he says, "I have mistrusted 'consciousness'as an entity; for seven or eight years past I have suggested itsnon-existence to my students, and tried to give them itspragmatic equivalent in realities of experience. It seems to methat the hour is ripe for it to be openly and universallydiscarded"(p. 3).

His next concern is to explain away the air of paradox, for Jameswas never wilfully paradoxical. "Undeniably," he says,"'thoughts' do exist." "I mean only to deny that the word standsfor an entity, but to insist most emphatically that it does standfor a function. There is, I mean, no aboriginal stuff or qualityof being, contrasted with that of which material objects aremade, out of which our thoughts of them are made; but there is afunction in experience which thoughts perform, and for theperformance of which this quality of being is invoked. Thatfunction is KNOWING"(pp. 3-4).

James's view is that the raw material out of which the world isbuilt up is not of two sorts, one matter and the other mind, butthat it is arranged in different patterns by its inter-relations,and that some arrangements may be called mental, while others maybe called physical.

"My thesis is," he says, "that if we start with the suppositionthat there is only one primal stuff or material in the world, astuff of which everything is composed, and if we call that stuff'pure experience,' then knowing can easily be explained as aparticular sort of relation towards one another into whichportions of pure experience may enter. The relation itself is apart of pure experience; one of its 'terms' becomes the subjector bearer of the knowledge, the knower, the other becomes theobject known"(p. 4).

After mentioning the duality of subject and object, which issupposed to constitute consciousness, he proceeds in italics:"EXPERIENCE, I BELIEVE, HAS NO SUCH INNER DUPLICITY; AND THESEPARATION OF IT INTO CONSCIOUSNESS AND CONTENT COMES, NOT BY WAYOF SUBTRACTION, BUT BY WAY OF ADDITION"(p. 9).

He illustrates his meaning by the analogy of paint as it appearsin a paint-shop and as it appears in a picture: in the one caseit is just "saleable matter," while in the other it "performs aspiritual function. Just so, I maintain (he continues), does agiven undivided portion of experience, taken in one context ofassociates, play the part of a knower, of a state of mind, of'consciousness'; while in a different context the same undividedbit of experience plays the part of a thing known, of anobjective 'content.' In a word, in one group it figures as athought, in another group as a thing"(pp. 9-10).

He does not believe in the supposed immediate certainty ofthought. "Let the case be what it may in others," he says, "I amas confident as I am of anything that, in myself, the stream ofthinking (which I recognize emphatically as a phenomenon) is onlya careless name for what, when scrutinized, reveals itself toconsist chiefly of the stream of my breathing. The 'I think'which Kant said must be able to accompany all my objects, is the'I breathe' which actually does accompany them"(pp. 36-37).

The same view of "consciousness" is set forth in the succeedingessay, "A World of Pure Experience" (ib., pp. 39-91). The use ofthe phrase "pure experience" in both essays points to a lingeringinfluence of idealism. "Experience," like "consciousness," mustbe a product, not part of the primary stuff of the world. It mustbe possible, if James is right in his main contentions, thatroughly the same stuff, differently arranged, would not give riseto anything that could be called "experience." This word has beendropped by the American realists, among whom we may mentionspecially Professor R. B. Perry of Harvard and Mr. Edwin B. Holt.The interests of this school are in general philosophy and thephilosophy of the sciences, rather than in psychology; they havederived a strong impulsion from James, but have more interestthan he had in logic and mathematics and the abstract part ofphilosophy. They speak of "neutral" entities as the stuff out ofwhich both mind and matter are constructed. Thus Holt says: "Ifthe terms and propositions of logic must be substantialized, theyare all strictly of one substance, for which perhaps the leastdangerous name is neutral- stuff. The relation of neutral-stuffto matter and mind we shall have presently to consider atconsiderable length." *

* "The Concept of Consciousness" (Geo. Allen & Co., 1914), p. 52.

My own belief--for which the reasons will appear in subsequentlectures--is that James is right in rejecting consciousness as anentity, and that the American realists are partly right, thoughnot wholly, in considering that both mind and matter are composedof a neutral-stuff which, in isolation, is neither mental normaterial. I should admit this view as regards sensations: what isheard or seen belongs equally to psychology and to physics. But Ishould say that images belong only to the mental world, whilethose occurrences (if any) which do not form part of any"experience" belong only to the physical world. There are, itseems to me, prima facie different kinds of causal laws, onebelonging to physics and the other to psychology. The law ofgravitation, for example, is a physical law, while the law ofassociation is a psychological law. Sensations are subject toboth kinds of laws, and are therefore truly "neutral" in Holt'ssense. But entities subject only to physical laws, or only topsychological laws, are not neutral, and may be calledrespectively purely material and purely mental. Even those,however, which are purely mental will not have that intrinsicreference to objects which Brentano assigns to them and whichconstitutes the essence of "consciousness" as ordinarilyunderstood. But it is now time to pass on to other moderntendencies, also hostile to "consciousness."

There is a psychological school called "Behaviourists," of whomthe protagonist is Professor John B. Watson,* formerly of theJohns Hopkins University. To them also, on the whole, belongsProfessor John Dewey, who, with James and Dr. Schiller, was oneof the three founders of pragmatism. The view of the"behaviourists" is that nothing can be known except by externalobservation. They deny altogether that there is a separate sourceof knowledge called "introspection," by which we can know thingsabout ourselves which we could never observe in others. They donot by any means deny that all sorts of things MAY go on in ourminds: they only say that such things, if they occur, are notsusceptible of scientific observation, and do not thereforeconcern psychology as a science. Psychology as a science, theysay, is only concerned with BEHAVIOUR, i.e. with what we DO; thisalone, they contend, can be accurately observed. Whether we thinkmeanwhile, they tell us, cannot be known; in their observation ofthe behaviour of human beings, they have not so far found anyevidence of thought. True, we talk a great deal, and imagine thatin so doing we are showing that we can think; but behaviouristssay that the talk they have to listen to can be explained withoutsupposing that people think. Where you might expect a chapter on"thought processes" you come instead upon a chapter on "TheLanguage Habit." It is humiliating to find how terribly adequatethis hypothesis turns out to be.

* See especially his "Behavior: an Introduction to ComparativePsychology," New York, 1914.

Behaviourism has not, however, sprung from observing the folly ofmen. It is the wisdom of animals that has suggested the view. Ithas always been a common topic of popular discussion whetheranimals "think." On this topic people are prepared to take sideswithout having the vaguest idea what they mean by "thinking."Those who desired to investigate such questions were led toobserve the behaviour of animals, in the hope that theirbehaviour would throw some light on their mental faculties. Atfirst sight, it might seem that this is so. People say that a dog"knows" its name because it comes when it is called, and that it"remembers" its master, because it looks sad in his absence, butwags its tail and barks when he returns. That the dog behaves inthis way is matter of observation, but that it "knows" or"remembers" anything is an inference, and in fact a very doubtfulone. The more such inferences are examined, the more precariousthey are seen to be. Hence the study of animal behaviour has beengradually led to abandon all attempt at mental interpretation.And it can hardly be doubted that, in many cases of complicatedbehaviour very well adapted to its ends, there can be noprevision of those ends. The first time a bird builds a nest, wecan hardly suppose it knows that there will be eggs to be laid init, or that it will sit on the eggs, or that they will hatch intoyoung birds. It does what it does at each stage because instinctgives it an impulse to do just that, not because it foresees anddesires the result of its actions.*

* An interesting discussion of the question whether instinctiveactions, when first performed, involve any prevision, howevervague, will be found in Lloyd Morgan's "Instinct and Experience"(Methuen, 1912), chap. ii.

Careful observers of animals, being anxious to avoid precariousinferences, have gradually discovered more and more how to givean account of the actions of animals without assuming what wecall "consciousness." It has seemed to the behaviourists thatsimilar methods can be applied to human behaviour, withoutassuming anything not open to external observation. Let us give acrude illustration, too crude for the authors in question, butcapable of affording a rough insight into their meaning. Supposetwo children in a school, both of whom are asked "What is sixtimes nine?" One says fifty-four, the other says fifty-six. Theone, we say, "knows" what six times nine is, the other does not.But all that we can observe is a certain language-habit. The onechild has acquired the habit of saying "six times nine isfifty-four"; the other has not. There is no more need of"thought" in this than there is when a horse turns into hisaccustomed stable; there are merely more numerous and complicatedhabits. There is obviously an observable fact called "knowing"such-and-such a thing; examinations are experiments fordiscovering such facts. But all that is observed or discovered isa certain set of habits in the use of words. The thoughts (ifany) in the mind of the examinee are of no interest to theexaminer; nor has the examiner any reason to suppose even themost successful examinee capable of even the smallest amount ofthought.

Thus what is called "knowing," in the sense in which we canascertain what other people "know," is a phenomenon exemplifiedin their physical behaviour, including spoken and written words.There is no reason--so Watson argues--to suppose that theirknowledge IS anything beyond the habits shown in this behaviour:the inference that other people have something nonphysical called"mind" or "thought" is therefore unwarranted.

So far, there is nothing particularly repugnant to our prejudicesin the conclusions of the behaviourists. We are all willing toadmit that other people are thoughtless. But when it comes toourselves, we feel convinced that we can actually perceive ourown thinking. "Cogito, ergo sum" would be regarded by most peopleas having a true premiss. This, however, the behaviourist denies.He maintains that our knowledge of ourselves is no different inkind from our knowledge of other people. We may see MORE, becauseour own body is easier to observe than that of other people; butwe do not see anything radically unlike what we see of others.Introspection, as a separate source of knowledge, is entirelydenied by psychologists of this school. I shall discuss thisquestion at length in a later lecture; for the present I willonly observe that it is by no means simple, and that, though Ibelieve the behaviourists somewhat overstate their case, yetthere is an important element of truth in their contention, sincethe things which we can discover by introspection do not seem todiffer in any very fundamental way from the things which wediscover by external observation.

So far, we have been principally concerned with knowing. But itmight well be maintained that desiring is what is really mostcharacteristic of mind. Human beings are constantly engaged inachieving some end they feel pleasure in success and pain infailure. In a purely material world, it may be said, there wouldbe no opposition of pleasant and unpleasant, good and bad, whatis desired and what is feared. A man's acts are governed bypurposes. He decides, let us suppose, to go to a certain place,whereupon he proceeds to the station, takes his ticket and entersthe train. If the usual route is blocked by an accident, he goesby some other route. All that he does is determined--or so itseems--by the end he has in view, by what lies in front of him,rather than by what lies behind. With dead matter, this is notthe case. A stone at the top of a hill may start rolling, but itshows no pertinacity in trying to get to the bottom. Any ledge orobstacle will stop it, and it will exhibit no signs of discontentif this happens. It is not attracted by the pleasantness of thevalley, as a sheep or cow might be, but propelled by thesteepness of the hill at the place where it is. In all this wehave characteristic differences between the behaviour of animalsand the behaviour of matter as studied by physics.

Desire, like knowledge, is, of course, in one sense an observablephenomenon. An elephant will eat a bun, but not a mutton chop; aduck will go into the water, but a hen will not. But when wethink of our own. desires, most people believe that we can knowthem by an immediate self-knowledge which does not depend uponobservation of our actions. Yet if this were the case, it wouldbe odd that people are so often mistaken as to what they desire.It is matter of common observation that "so-and-so does not knowhis own motives," or that "A is envious of B and malicious abouthim, but quite unconscious of being so." Such people are calledself-deceivers, and are supposed to have had to go through somemore or less elaborate process of concealing from themselves whatwould otherwise have been obvious. I believe that this is anentire mistake. I believe that the discovery of our own motivescan only be made by the same process by which we discover otherpeople's, namely, the process of observing our actions andinferring the desire which could prompt them. A desire is"conscious" when we have told ourselves that we have it. A hungryman may say to himself: "Oh, I do want my lunch." Then his desireis "conscious." But it only differs from an "unconscious" desireby the presence of appropriate words, which is by no means afundamental difference.

The belief that a motive is normally conscious makes it easier tobe mistaken as to our own motives than as to other people's. Whensome desire that we should be ashamed of is attributed to us, wenotice that we have never had it consciously, in the sense ofsaying to ourselves, "I wish that would happen." We thereforelook for some other interpretation of our actions, and regard ourfriends as very unjust when they refuse to be convinced by ourrepudiation of what we hold to be a calumny. Moral considerationsgreatly increase the difficulty of clear thinking in this matter.It is commonly argued that people are not to blame forunconscious motives, but only for conscious ones. In order,therefore, to be wholly virtuous it is only necessary to repeatvirtuous formulas. We say: "I desire to be kind to my friends,honourable in business, philanthropic towards the poor,public-spirited in politics." So long as we refuse to allowourselves, even in the watches of the night, to avow any contrarydesires, we may be bullies at home, shady in the City, skinflintsin paying wages and profiteers in dealing with the public; yet,if only conscious motives are to count in moral valuation, weshall remain model characters. This is an agreeable doctrine, andit is not surprising that men are un willing to abandon it. Butmoral considerations are the worst enemies of the scientificspirit and we must dismiss them from our minds if we wish toarrive at truth.

I believe--as I shall try to prove in a later lecture -thatdesire, like force in mechanics, is of the nature of a convenientfiction for describing shortly certain laws of behaviour. Ahungry animal is restless until it finds food; then it becomesquiescent. The thing which will bring a restless condition to anend is said to be what is desired. But only experience can showwhat will have this sedative effect, and it is easy to makemistakes. We feel dissatisfaction, and think that such and-such athing would remove it; but in thinking this, we are theorizing,not observing a patent fact. Our theorizing is often mistaken,and when it is mistaken there is a difference between what wethink we desire and what in fact will bring satisfaction. This issuch a common phenomenon that any theory of desire which fails toaccount for it must be wrong.

What have been called "unconscious" desires have been broughtvery much to the fore in recent years by psycho-analysis.Psycho-analysis, as every one knows, is primarily a method ofunderstanding hysteria and certain forms of insanity*; but it hasbeen found that there is much in the lives of ordinary men andwomen which bears a humiliating resemblance to the delusions ofthe insane. The connection of dreams, irrational beliefs andfoolish actions with unconscious wishes has been brought tolight, though with some exaggeration, by Freud and Jung and theirfollowers. As regards the nature of these unconscious wishes, itseems to me--though as a layman I speak with diffidence--thatmany psycho-analysts are unduly narrow; no doubt the wishes theyemphasize exist, but others, e.g. for honour and power, areequally operative and equally liable to concealment. This,however, does not affect the value of their general theories fromthe point of view of theoretic psychology, and it is from thispoint of view that their results are important for the analysisof mind.

* There is a wide field of "unconscious" phenomena which does notdepend upon psycho-analytic theories. Such occurrences asautomatic writing lead Dr. Morton Prince to say: "As I view thisquestion of the subconscious, far too much weight is given to thepoint of awareness or not awareness of our conscious processes.As a matter of fact, we find entirely identical phenomena, thatis, identical in every respect but one-that of awareness in whichsometimes we are aware of these conscious phenomena and sometimesnot"(p. 87 of "Subconscious Phenomena," by various authors,Rebman). Dr. Morton Price conceives that there may be"consciousness" without "awareness." But this is a difficultview, and one which makes some definition of "consciousness"imperative. For nay part, I cannot see how to separateconsciousness from awareness.

What, I think, is clearly established, is that a man's actionsand beliefs may be wholly dominated by a desire of which he isquite unconscious, and which he indignantly repudiates when it issuggested to him. Such a desire is generally, in morbid cases, ofa sort which the patient would consider wicked; if he had toadmit that he had the desire, he would loathe himself. Yet it isso strong that it must force an outlet for itself; hence itbecomes necessary to entertain whole systems of false beliefs inorder to hide the nature of what is desired. The resultingdelusions in very many cases disappear if the hysteric or lunaticcan be made to face the facts about himself. The consequence ofthis is that the treatment of many forms of insanity has grownmore psychological and less physiological than it used to be.Instead of looking for a physical defect in the brain, those whotreat delusions look for the repressed desire which has foundthis contorted mode of expression. For those who do not wish toplunge into the somewhat repulsive and often rather wild theoriesof psychoanalytic pioneers, it will be worth while to read alittle book by Dr. Bernard Hart on "The Psychology of Insanity."*On this question of the mental as opposed to the physiologicalstudy of the causes of insanity, Dr. Hart says:

* Cambridge, 1912; 2nd edition, 1914. The following referencesare to the second edition.

"The psychological conception [of insanity] is based on the viewthat mental processes can be directly studied without anyreference to the accompanying changes which are presumed to takeplace in the brain, and that insanity may therefore be properlyattacked from the standpoint of psychology"(p. 9).

This illustrates a point which I am anxious to make clear fromthe outset. Any attempt to classify modern views, such as Ipropose to advocate, from the old standpoint of materialism andidealism, is only misleading. In certain respects, the viewswhich I shall be setting forth approximate to materialism; incertain others, they approximate to its opposite. On thisquestion of the study of delusions, the practical effect of themodern theories, as Dr. Hart points out, is emancipation from thematerialist method. On the other hand, as he also points out (pp.38-9), imbecility and dementia still have to be consideredphysiologically, as caused by defects in the brain. There is noinconsistency in this If, as we maintain, mind and matter areneither of them the actual stuff of reality, but differentconvenient groupings of an underlying material, then, clearly,the question whether, in regard to a given phenomenon, we are toseek a physical or a mental cause, is merely one to be decided bytrial. Metaphysicians have argued endlessly as to the interactionof mind and matter. The followers of Descartes held that mind andmatter are so different as to make any action of the one on theother impossible. When I will to move my arm, they said, it isnot my will that operates on my arm, but God, who, by Hisomnipotence, moves my arm whenever I want it moved. The moderndoctrine of psychophysical parallelism is not appreciablydifferent from this theory of the Cartesian school.Psycho-physical parallelism is the theory that mental andphysical events each have causes in their own sphere, but run onside by side owing to the fact that every state of the braincoexists with a definite state of the mind, and vice versa. Thisview of the reciprocal causal independence of mind and matter hasno basis except in metaphysical theory.* For us, there is nonecessity to make any such assumption, which is very difficult toharmonize with obvious facts. I receive a letter inviting me todinner: the letter is a physical fact, but my apprehension of itsmeaning is mental. Here we have an effect of matter on mind. Inconsequence of my apprehension of the meaning of the letter, I goto the right place at the right time; here we have an effect ofmind on matter. I shall try to persuade you, in the course ofthese lectures, that matter is not so material and mind not somental as is generally supposed. When we are speaking of matter,it will seem as if we were inclining to idealism; when we arespeaking of mind, it will seem as if we were inclining tomaterialism. Neither is the truth. Our world is to be constructedout of what the American realists call "neutral" entities, whichhave neither the hardness and indestructibility of matter, northe reference to objects which is supposed to characterize mind.

* It would seem, however, that Dr. Hart accepts this theory as 8methodological precept. See his contribution to "SubconsciousPhenomena" (quoted above), especially pp. 121-2.

There is, it is true, one objection which might be felt, notindeed to the action of matter on mind, but to the action of mindon matter. The laws of physics, it may be urged, are apparentlyadequate to explain everything that happens to matter, even whenit is matter in a man's brain. This, however, is only ahypothesis, not an established theory. There is no cogentempirical reason for supposing that the laws determining themotions of living bodies are exactly the same as those that applyto dead matter. Sometimes, of course, they are clearly the same.When a man falls from a precipice or slips on a piece of orangepeel, his body behaves as if it were devoid of life. These arethe occasions that make Bergson laugh. But when a man's bodilymovements are what we call "voluntary," they are, at any rateprima facie, very different in their laws from the movements ofwhat is devoid of life. I do not wish to say dogmatically thatthe difference is irreducible; I think it highly probable that itis not. I say only that the study of the behaviour of livingbodies, in the present state of our knowledge, is distinct fromphysics. The study of gases was originally quite distinct fromthat of rigid bodies, and would never have advanced to itspresent state if it had not been independently pursued. Nowadaysboth the gas and the rigid body are manufactured out of a moreprimitive and universal kind of matter. In like manner, as aquestion of methodology, the laws of living bodies are to bestudied, in the first place, without any undue haste tosubordinate them to the laws of physics. Boyle's law and the resthad to be discovered before the kinetic theory of gases becamepossible. But in psychology we are hardly yet at the stage ofBoyle's law. Meanwhile we need not be held up by the bogey of theuniversal rigid exactness of physics. This is, as yet, a merehypothesis, to be tested empirically without any preconceptions.It may be true, or it may not. So far, that is all we can say.

Returning from this digression to our main topic, namely, thecriticism of "consciousness," we observe that Freud and hisfollowers, though they have demonstrated beyond dispute theimmense importance of "unconscious" desires in determining ouractions and beliefs, have not attempted the task of telling uswhat an "unconscious" desire actually is, and have thus investedtheir doctrine with an air of mystery and mythology which forms alarge part of its popular attractiveness. They speak always asthough it were more normal for a desire to be conscious, and asthough a positive cause had to be assigned for its beingunconscious. Thus "the unconscious" becomes a sort of undergroundprisoner, living in a dungeon, breaking in at long intervals uponour daylight respectability with dark groans and maledictions andstrange atavistic lusts. The ordinary reader, almost inevitably,thinks of this underground person as another consciousness,prevented by what Freud calls the "censor" from making his voiceheard in company, except on rare and dreadful occasions when heshouts so loud that every one hears him and there is a scandal.Most of us like the idea that we could be desperately wicked ifonly we let ourselves go. For this reason, the Freudian"unconscious" has been a consolation to many quiet andwell-behaved persons.

I do not think the truth is quite so picturesque as this. Ibelieve an "unconscious" desire is merely a causal law of ourbehaviour,* namely, that we remain restlessly active until acertain state of affairs is realized, when we achieve temporaryequilibrium If we know beforehand what this state of affairs is,our desire is conscious; if not, unconscious. The unconsciousdesire is not something actually existing, but merely a tendencyto a certain behaviour; it has exactly the same status as a forcein dynamics. The unconscious desire is in no way mysterious; itis the natural primitive form of desire, from which the other hasdeveloped through our habit of observing and theorizing (oftenwrongly). It is not necessary to suppose, as Freud seems to do,that every unconscious wish was once conscious, and was then, inhis terminology, "repressed" because we disapproved of it. On thecontrary, we shall suppose that, although Freudian "repression"undoubtedly occurs and is important, it is not the usual reasonfor unconsciousness of our wishes. The usual reason is merelythat wishes are all, to begin with, unconscious, and only becomeknown when they are actively noticed. Usually, from laziness,people do not notice, but accept the theory of human nature whichthey find current, and attribute to themselves whatever wishesthis theory would lead them to expect. We used to be full ofvirtuous wishes, but since Freud our wishes have become, in thewords of the Prophet Jeremiah, "deceitful above all things anddesperately wicked." Both these views, in most of those who haveheld them, are the product of theory rather than observation, forobservation requires effort, whereas repeating phrases does not.

* Cf. Hart, "The Psychology of Insanity," p. 19.

The interpretation of unconscious wishes which I have beenadvocating has been set forth briefly by Professor John B. Watsonin an article called "The Psychology of Wish Fulfilment," whichappeared in "The Scientific Monthly" in November, 1916. Twoquotations will serve to show his point of view:

"The Freudians (he says) have made more or less of a'metaphysical entity' out of the censor. They suppose that whenwishes are repressed they are repressed into the 'unconscious,'and that this mysterious censor stands at the trapdoor lyingbetween the conscious and the unconscious. Many of us do notbelieve in a world of the unconscious (a few of us even havegrave doubts about the usefulness of the term consciousness),hence we try to explain censorship along ordinary biologicallines. We believe that one group of habits can 'down' anothergroup of habits--or instincts. In this case our ordinary systemof habits--those which we call expressive of our 'real selves'--inhibit or quench (keep inactive or partially inactive) thosehabits and instinctive tendencies which belong largely in thepast"(p. 483).

Again, after speaking of the frustration of some impulses whichis involved in acquiring the habits of a civilized adult, hecontinues:

"It is among these frustrated impulses that I would find thebiological basis of the unfulfilled wish. Such 'wishes' neednever have been 'conscious,' and NEED NEVER HAVE BEEN SUPPRESSEDINTO FREUD'S REALM OF THE UNCONSCIOUS. It may be inferred fromthis that there is no particular reason for applying the term'wish' to such tendencies"(p. 485).

One of the merits of the general analysis of mind which we shallbe concerned with in the following lectures is that it removesthe atmosphere of mystery from the phenomena brought to light bythe psycho-analysts. Mystery is delightful, but unscientific,since it depends upon ignorance. Man has developed out of theanimals, and there is no serious gap between him and the amoeba.Something closely analogous to knowledge and desire, as regardsits effects on behaviour, exists among animals, even where whatwe call "consciousness" is hard to believe in; something equallyanalogous exists in ourselves in cases where no trace of"consciousness" can be found. It is therefore natural to supposethat, what ever may be the correct definition of "consciousness,""consciousness" is not the essence of life or mind. In thefollowing lectures, accordingly, this term will disappear untilwe have dealt with words, when it will re-emerge as mainly atrivial and unimportant outcome of linguistic habits.

LECTURE II. INSTINCT AND HABIT

In attempting to understand the elements out of which mentalphenomena are compounded, it is of the greatest importance toremember that from the protozoa to man there is nowhere a verywide gap either in structure or in behaviour. From this fact itis a highly probable inference that there is also nowhere a verywide mental gap. It is, of course, POSSIBLE that there may be, atcertain stages in evolution, elements which are entirely new fromthe standpoint of analysis, though in their nascent form theyhave little influence on behaviour and no very markedcorrelatives in structure. But the hypothesis of continuity inmental development is clearly preferable if no psychologicalfacts make it impossible. We shall find, if I am not mistaken,that there are no facts which refute the hypothesis of mentalcontinuity, and that, on the other hand, this hypothesis affordsa useful test of suggested theories as to the nature of mind.

The hypothesis of mental continuity throughout organic evolutionmay be used in two different ways. On the one hand, it may beheld that we have more knowledge of our own minds than those ofanimals, and that we should use this knowledge to infer theexistence of something similar to our own mental processes inanimals and even in plants. On the other hand, it may be heldthat animals and plants present simpler phenomena, more easilyanalysed than those of human minds; on this ground it may beurged that explanations which are adequate in the case of animalsought not to be lightly rejected in the case of man. Thepractical effects of these two views are diametrically opposite:the first leads us to level up animal intelligence with what webelieve ourselves to know about our own intelligence, while thesecond leads us to attempt a levelling down of our ownintelligence to something not too remote from what we can observein animals. It is therefore important to consider the relativejustification of the two ways of applying the principle ofcontinuity.

It is clear that the question turns upon another, namely, whichcan we know best, the psychology of animals or that of humanbeings? If we can know most about animals, we shall use thisknowledge as a basis for inference about human beings; if we canknow most about human beings, we shall adopt the oppositeprocedure. And the question whether we can know most about thepsychology of human beings or about that of animals turns uponyet another, namely: Is introspection or external observation thesurer method in psychology? This is a question which I propose todiscuss at length in Lecture VI; I shall therefore content myselfnow with a statement of the conclusions to be arrived at.

We know a great many things concerning ourselves which we cannotknow nearly so directly concerning animals or even other people.We know when we have a toothache, what we are thinking of, whatdreams we have when we are asleep, and a host of otheroccurrences which we only know about others when they tell us ofthem, or otherwise make them inferable by their behaviour. Thus,so far as knowledge of detached facts is concerned, the advantageis on the side of self-knowledge as against external observation.

But when we come to the analysis and scientific understanding ofthe facts, the advantages on the side of self-knowledge becomefar less clear. We know, for example, that we have desires andbeliefs, but we do not know what constitutes a desire or abelief. The phenomena are so familiar that it is difficult torealize how little we really know about them. We see in animals,and to a lesser extent in plants, behaviour more or less similarto that which, in us, is prompted by desires and beliefs, and wefind that, as we descend in the scale of evolution, behaviourbecomes simpler, more easily reducible to rule, morescientifically analysable and predictable. And just because weare not misled by familiarity we find it easier to be cautious ininterpreting behaviour when we are dealing with phenomena remotefrom those of our own minds: Moreover, introspection, aspsychoanalysis has demonstrated, is extraordinarily fallible evenin cases where we feel a high degree of certainty. The net resultseems to be that, though self-knowledge has a definite andimportant contribution to make to psychology, it is exceedinglymisleading unless it is constantly checked and controlled by thetest of external observation, and by the theories which suchobservation suggests when applied to animal behaviour. On thewhole, therefore, there is probably more to be learnt about humanpsychology from animals than about animal psychology from humanbeings; but this conclusion is one of degree, and must not bepressed beyond a point.

It is only bodily phenomena that can be directly observed inanimals, or even, strictly speaking, in other human beings. Wecan observe such things as their movements, their physiologicalprocesses, and the sounds they emit. Such things as desires andbeliefs, which seem obvious to introspection, are not visibledirectly to external observation. Accordingly, if we begin ourstudy of psychology by external observation, we must not begin byassuming such things as desires and beliefs, but only such thingsas external observation can reveal, which will be characteristicsof the movements and physiological processes of animals. Someanimals, for example, always run away from light and hidethemselves in dark places. If you pick up a mossy stone which islightly embedded in the earth, you will see a number of smallanimals scuttling away from the unwonted daylight and seekingagain the darkness of which you have deprived them. Such animalsare sensitive to light, in the sense that their movements areaffected by it; but it would be rash to infer that they havesensations in any way analogous to our sensations of sight. Suchinferences, which go beyond the observable facts, are to beavoided with the utmost care.

It is customary to divide human movements into three classes,voluntary, reflex and mechanical. We may illustrate thedistinction by a quotation from William James ("Psychology," i,12):

"If I hear the conductor calling 'all aboard' as I enter thedepot, my heart first stops, then palpitates, and my legs respondto the air-waves falling on my tympanum by quickening theirmovements. If I stumble as I run, the sensation of fallingprovokes a movement of the hands towards the direction of thefall, the effect of which is to shield the body from too sudden ashock. If a cinder enter my eye, its lids close forcibly and acopious flow of tears tends to wash it out.

"These three responses to a sensational stimulus differ, however,in many respects. The closure of the eye and the lachrymation arequite involuntary, and so is the disturbance of the heart. Suchinvoluntary responses we know as 'reflex' acts. The motion of thearms to break the shock of falling may also be called reflex,since it occurs too quickly to be deliberately intended. Whetherit be instinctive or whether it result from the pedestrianeducation of childhood may be doubtful; it is, at any rate, lessautomatic than the previous acts, for a man might by consciouseffort learn to perform it more skilfully, or even to suppress italtogether. Actions of this kind, with which instinct andvolition enter upon equal terms, have been called 'semi-reflex.'The act of running towards the train, on the other hand, has noinstinctive element about it. It is purely the result ofeducation, and is preceded by a consciousness of the purpose tobe attained and a distinct mandate of the will. It is a'voluntary act.' Thus the animal's reflex and voluntaryperformances shade into each other gradually, being connected byacts which may often occur automatically, but may also bemodified by conscious intelligence.

"An outside observer, unable to perceive the accompanyingconsciousness, might be wholly at a loss to discriminate betweenthe automatic acts and those which volition escorted. But if thecriterion of mind's existence be the choice of the proper meansfor the attainment of a supposed end, all the acts alike seem tobe inspired by intelligence, for APPROPRIATENESS characterizesthem all alike. "

There is one movement, among those that James mentions at first,which is not subsequently classified, namely, the stumbling. Thisis the kind of movement which may be called "mechanical"; it isevidently of a different kind from either reflex or voluntarymovements, and more akin to the movements of dead matter. We maydefine a movement of an animal's body as "mechanical" when itproceeds as if only dead matter were involved. For example, ifyou fall over a cliff, you move under the influence ofgravitation, and your centre of gravity describes just as correcta parabola as if you were already dead. Mechanical movements havenot the characteristic of appropriateness, unless by accident, aswhen a drunken man falls into a waterbutt and is sobered. Butreflex and voluntary movements are not ALWAYS appropriate, unlessin some very recondite sense. A moth flying into a lamp is notacting sensibly; no more is a man who is in such a hurry to gethis ticket that he cannot remember the name of his destination.Appropriateness is a complicated and merely approximate idea, andfor the present we shall do well to dismiss it from our thoughts.

As James states, there is no difference, from the point of viewof the outside observer, between voluntary and reflex movements.The physiologist can discover that both depend upon the nervoussystem, and he may find that the movements which we callvoluntary depend upon higher centres in the brain than those thatare reflex. But he cannot discover anything as to the presence orabsence of "will" or "consciousness," for these things can onlybe seen from within, if at all. For the present, we wish to placeourselves resolutely in the position of outside observers; wewill therefore ignore the distinction between voluntary andreflex movements. We will call the two together "vital"movements. We may then distinguish "vital" from mechanicalmovements by the fact that vital movements depend for theircausation upon the special properties of the nervous system,while mechanical movements depend only upon the properties whichanimal bodies share with matter in general.

There is need for some care if the distinction between mechanicaland vital movements is to be made precise. It is quite likelythat, if we knew more about animal bodies, we could deduce alltheir movements from the laws of chemistry and physics. It isalready fairly easy to see how chemistry reduces to physics, i.e.how the differences between different chemical elements can beaccounted for by differences of physical structure, theconstituents of the structure being electrons which are exactlyalike in all kinds of matter. We only know in part how to reducephysiology to chemistry, but we know enough to make it likelythat the reduction is possible. If we suppose it effected, whatwould become of the difference between vital and mechanicalmovements?

Some analogies will make the difference clear. A shock to a massof dynamite produces quite different effects from an equal shockto a mass of steel: in the one case there is a vast explosion,while in the other case there is hardly any noticeabledisturbance. Similarly, you may sometimes find on a mountain-sidea large rock poised so delicately that a touch will set itcrashing down into the valley, while the rocks all round are sofirm that only a considerable force can dislodge them What isanalogous in these two cases is the existence of a great store ofenergy in unstable equilibrium ready to burst into violent motionby the addition of a very slight disturbance. Similarly, itrequires only a very slight expenditure of energy to send apost-card with the words "All is discovered; fly!" but the effectin generating kinetic energy is said to be amazing. A human body,like a mass of dynamite, contains a store of energy in unstableequilibrium, ready to be directed in this direction or that by adisturbance which is physically very small, such as a spokenword. In all such cases the reduction of behaviour to physicallaws can only be effected by entering into great minuteness; solong as we confine ourselves to the observation of comparativelylarge masses, the way in which the equilibrium will be upsetcannot be determined. Physicists distinguish between macroscopicand microscopic equations: the former determine the visiblemovements of bodies of ordinary size, the latter the minuteoccurrences in the smallest parts. It is only the microscopicequations that are supposed to be the same for all sorts ofmatter. The macroscopic equations result from a process ofaveraging out, and may be different in different cases. So, inour instance, the laws of macroscopic phenomena are different formechanical and vital movements, though the laws of microscopicphenomena may be the same.

We may say, speaking somewhat roughly, that a stimulus applied tothe nervous system, like a spark to dynamite, is able to takeadvantage of the stored energy in unstable equilibrium, and thusto produce movements out of proportion to the proximate cause.Movements produced in this way are vital movements, whilemechanical movements are those in which the stored energy of aliving body is not involved. Similarly dynamite may be exploded,thereby displaying its characteristic properties, or may (withdue precautions) be carted about like any other mineral. Theexplosion is analogous to vital movements, the carting about tomechanical movements.

Mechanical movements are of no interest to the psychologist, andit has only been necessary to define them in order to be able toexclude them. When a psychologist studies behaviour, it is onlyvital movements that concern him. We shall, therefore, proceed toignore mechanical movements, and study only the properties of theremainder.

The next point is to distinguish between movements that areinstinctive and movements that are acquired by experience. Thisdistinction also is to some extent one of degree. Professor LloydMorgan gives the following definition of "instinctive behaviour":

"That which is, on its first occurrence, independent of priorexperience; which tends to the well-being of the individual andthe preservation of the race; which is similarly performed by allmembers of the same more or less restricted group of animals; andwhich may be subject to subsequent modification under theguidance of experience." *

* "Instinct and Experience" (Methuen, 1912) p. 5.

This definition is framed for the purposes of biology, and is insome respects unsuited to the needs of psychology. Though perhapsunavoidable, allusion to "the same more or less restricted groupof animals" makes it impossible to judge what is instinctive inthe behaviour of an isolated individual. Moreover, "thewell-being of the individual and the preservation of the race" isonly a usual characteristic, not a universal one, of the sort ofmovements that, from our point of view, are to be calledinstinctive; instances of harmful instincts will be givenshortly. The essential point of the definition, from our point ofview, is that an instinctive movement is in dependent of priorexperience.

We may say that an "instinctive" movement is a vital movementperformed by an animal the first time that it finds itself in anovel situation; or, more correctly, one which it would performif the situation were novel.* The instincts of an animal aredifferent at different periods of its growth, and this fact maycause changes of behaviour which are not due to learning. Thematuring and seasonal fluctuation of the sex-instinct affords agood illustration. When the sex-instinct first matures, thebehaviour of an animal in the presence of a mate is differentfrom its previous behaviour in similar circumstances, but is notlearnt, since it is just the same if the animal has neverpreviously been in the presence of a mate.

* Though this can only be decided by comparison with othermembers of the species, and thus exposes us to the need ofcomparison which we thought an objection to Professor LloydMorgan's definition.

On the other hand, a movement is "learnt," or embodies a "habit,"if it is due to previous experience of similar situations, and isnot what it would be if the animal had had no such experience.

There are various complications which blur the sharpness of thisdistinction in practice. To begin with, many instincts maturegradually, and while they are immature an animal may act in afumbling manner which is very difficult to distinguish fromlearning. James ("Psychology," ii, 407) maintains that childrenwalk by instinct, and that the awkwardness of their firstattempts is only due to the fact that the instinct has not yetripened. He hopes that "some scientific widower, left alone withhis offspring at the critical moment, may ere long test thissuggestion on the living subject." However this may be, he quotesevidence to show that "birds do not LEARN to fly," but fly byinstinct when they reach the appropriate age (ib., p. 406). Inthe second place, instinct often gives only a rough outline ofthe sort of thing to do, in which case learning is necessary inorder to acquire certainty and precision in action. In the thirdplace, even in the clearest cases of acquired habit, such asspeaking, some instinct is required to set in motion the processof learning. In the case of speaking, the chief instinct involvedis commonly supposed to be that of imitation, but this may bequestioned. (See Thorndike's "Animal Intelligence," p. 253 ff.)

In spite of these qualifications, the broad distinction betweeninstinct and habit is undeniable. To take extreme cases, everyanimal at birth can take food by instinct, before it has hadopportunity to learn; on the other hand, no one can ride abicycle by instinct, though, after learning, the necessarymovements become just as automatic as if they were instinctive.

The process of learning, which consists in the acquisition ofhabits, has been much studied in various animals.* For example:you put a hungry animal, say a cat, in a cage which has a doorthat can be opened by lifting a latch; outside the cage you putfood. The cat at first dashes all round the cage, making franticefforts to force a way out. At last, by accident, the latch islifted. and the cat pounces on the food. Next day you repeat theexperiment, and you find that the cat gets out much more quicklythan the first time, although it still makes some randommovements. The third day it gets out still more quickly, andbefore long it goes straight to the latch and lifts it at once.Or you make a model of the Hampton Court maze, and put a rat inthe middle, assaulted by the smell of food on the outside. Therat starts running down the passages, and is constantly stoppedby blind alleys, but at last, by persistent attempts, it getsout. You repeat this experiment day after day; you measure thetime taken by the rat in reaching the food; you find that thetime rapidly diminishes, and that after a while the rat ceases tomake any wrong turnings. It is by essentially similar processesthat we learn speaking, writing, mathematics, or the governmentof an empire.

* The scientific study of this subject may almost be said tobegin with Thorndike's "Animal Intelligence" (Macmillan, 1911).

Professor Watson ("Behavior," pp. 262-3) has an ingenious theoryas to the way in which habit arises out of random movements. Ithink there is a reason why his theory cannot be regarded asalone sufficient, but it seems not unlikely that it is partlycorrect. Suppose, for the sake of simplicity, that there are justten random movements which may be made by the animal--say, tenpaths down which it may go--and that only one of these leads tofood, or whatever else represents success in the case inquestion. Then the successful movement always occurs during theanimal's attempts, whereas each of the others, on the average,occurs in only half the attempts. Thus the tendency to repeat aprevious performance (which is easily explicable without theintervention of "consciousness") leads to a greater emphasis onthe successful movement than on any other, and in time causes italone to be performed. The objection to this view, if taken asthe sole explanation, is that on improvement ought to set in tillafter the SECOND trial, whereas experiment shows that already atthe second attempt the animal does better than the first time.Something further is, therefore, required to account for thegenesis of habit from random movements; but I see no reason tosuppose that what is further required involves "consciousness."

"The Law of Effect is that: Of several responses made to the samesituation, those which are accompanied or closely followed bysatisfaction to the animal will, other things being equal, bemore firmly connected with the situation, so that, when itrecurs, they will be more likely to recur; those which areaccompanied or closely followed by discomfort to the animal will,other things being equal, have their connections with thatsituation weakened, so that, when it recurs, they will be lesslikely to occur. The greater the satisfaction or discomfort, thegreater the strengthening or weakening of the bond.

"The Law of Exercise is that: Any response to a situation will,other things being equal, be more strongly connected with thesituation in proportion to the number of times it has beenconnected with that situation and to the average vigour andduration of the connections."

With the explanation to be presently given of the meaning of"satisfaction" and "discomfort," there seems every reason toaccept these two laws.

What is true of animals, as regards instinct and habit, isequally true of men. But the higher we rise in the evolutionaryscale, broadly speaking, the greater becomes the power oflearning, and the fewer are the occasions when pure instinct isexhibited unmodified in adult life. This applies with great forceto man, so much so that some have thought instinct less importantin the life of man than in that of animals. This, however, wouldbe a mistake. Learning is only possible when instinct suppliesthe driving-force. The animals in cages, which gradually learn toget out, perform random movements at first, which are purelyinstinctive. But for these random movements, they would neveracquire the experience which afterwards enables them to producethe right movement. (This is partly questioned by Hobhouse*--wrongly, I think.) Similarly, children learning to talk make allsorts of sounds, until one day the right sound comes by accident.It is clear that the original making of random sounds, withoutwhich speech would never be learnt, is instinctive. I think wemay say the same of all the habits and aptitudes that we acquirein all of them there has been present throughout some instinctiveactivity, prompting at first rather inefficient movements, butsupplying the driving force while more and more effective methodsare being acquired. A cat which is hungry smells fish, and goesto the larder. This is a thoroughly efficient method when thereis fish in the larder, and it is often successfully practised bychildren. But in later life it is found that merely going to thelarder does not cause fish to be there; after a series of randommovements it is found that this result is to be caused by goingto the City in the morning and coming back in the evening. No onewould have guessed a priori that this movement of a middle-agedman's body would cause fish to come out of the sea into hislarder, but experience shows that it does, and the middle-agedman therefore continues to go to the City, just as the cat in thecage continues to lift the latch when it has once found it. Ofcourse, in actual fact, human learning is rendered easier, thoughpsychologically more complex, through language; but at bottomlanguage does not alter the essential character of learning, orof the part played by instinct in promoting learning. Language,however, is a subject upon which I do not wish to speak until alater lecture.

* "Mind in Evolution" (Macmillan, 1915), pp. 236-237.

The popular conception of instinct errs by imagining it to beinfallible and preternaturally wise, as well as incapable ofmodification. This is a complete delusion. Instinct, as a rule,is very rough and ready, able to achieve its result underordinary circumstances, but easily misled by anything unusual.Chicks follow their mother by instinct, but when they are quiteyoung they will follow with equal readiness any moving objectremotely resembling their mother, or even a human being (James,"Psychology," ii, 396). Bergson, quoting Fabre, has made playwith the supposed extraordinary accuracy of the solitary waspAmmophila, which lays its eggs in a caterpillar. On this subjectI will quote from Drever's "Instinct in Man," p. 92:

"According to Fabre's observations, which Bergson accepts, theAmmophila stings its prey EXACTLY and UNERRINGLY in EACH of thenervous centres. The result is that the caterpillar is paralyzed,but not immediately killed, the advantage of this being that thelarva cannot be injured by any movement of the caterpillar, uponwhich the egg is deposited, and is provided with fresh meat whenthe time comes.

"Now Dr. and Mrs. Peckham have shown that the sting of the waspis NOT UNERRING, as Fabre alleges, that the number of stings isNOT CONSTANT, that sometimes the caterpillar is NOT PARALYZED,and sometimes it is KILLED OUTRIGHT, and that THE DIFFERENTCIRCUMSTANCES DO NOT APPARENTLY MAKE ANY DIFFERENCE TO THE LARVA,which is not injured by slight movements of the caterpillar, norby consuming food decomposed rather than fresh caterpillar."

This illustrates how love of the marvellous may mislead even socareful an observer as Fabre and so eminent a philosopher asBergson.

In the same chapter of Dr. Drever's book there are someinteresting examples of the mistakes made by instinct. I willquote one as a sample:

"The larva of the Lomechusa beetle eats the young of the ants, inwhose nest it is reared. Nevertheless, the ants tend theLomechusa larvae with the same care they bestow on their ownyoung. Not only so, but they apparently discover that the methodsof feeding, which suit their own larvae, would prove fatal to theguests, and accordingly they change their whole system ofnursing" (loc. cit., p. 106).

Semon ("Die Mneme," pp. 207-9) gives a good illustration of aninstinct growing wiser through experience. He relates how huntersattract stags by imitating the sounds of other members of theirspecies, male or female, but find that the older a stag becomesthe more difficult it is to deceive him, and the more accuratethe imitation has to be. The literature of instinct is vast, andillustrations might be multiplied indefinitely. The main pointsas regards instinct, which need to be emphasized as against thepopular conceptions of it, are:

(1) That instinct requires no prevision of the biological endwhich it serves;

(2) That instinct is only adapted to achieve this end in theusual circumstances of the animal in question, and has no moreprecision than is necessary for success AS A RULE;

(3) That processes initiated by instinct often come to beperformed better after experience;

(4) That instinct supplies the impulses to experimental movementswhich are required for the process of learning;

(5) That instincts in their nascent stages are easily modifiable,and capable of being attached to various sorts of objects.

All the above characteristics of instinct can be established bypurely external observation, except the fact that instinct doesnot require prevision. This, though not strictly capable of beingPROVED by observation, is irresistibly suggested by the mostobvious phenomena. Who can believe, for example, that a new-bornbaby is aware of the necessity of food for preserving life? Orthat insects, in laying eggs, are concerned for the preservationof their species? The essence of instinct, one might say, is thatit provides a mechanism for acting without foresight in a mannerwhich is usually advantageous biologically. It is partly for thisreason that it is so important to understand the fundamentalposition of instinct in prompting both animal and humanbehaviour.

LECTURE III. DESIRE AND FEELING

Desire is a subject upon which, if I am not mistaken, true viewscan only be arrived at by an almost complete reversal of theordinary unreflecting opinion. It is natural to regard desire asin its essence an attitude towards something which is imagined,not actual; this something is called the END or OBJECT of thedesire, and is said to be the PURPOSE of any action resultingfrom the desire. We think of the content of the desire as beingjust like the content of a belief, while the attitude taken uptowards the content is different. According to this theory, whenwe say: "I hope it will rain," or "I expect it will rain," weexpress, in the first case, a desire, and in the second, abelief, with an identical content, namely, the image of rain. Itwould be easy to say that, just as belief is one kind of feelingin relation to this content, so desire is another kind. Accordingto this view, what comes first in desire is something imagined,with a specific feeling related to it, namely, that specificfeeling which we call "desiring" it. The discomfort associatedwith unsatisfied desire, and the actions which aim at satisfyingdesire, are, in this view, both of them effects of the desire. Ithink it is fair to say that this is a view against which commonsense would not rebel; nevertheless, I believe it to be radicallymistaken. It cannot be refuted logically, but various facts canbe adduced which make it gradually less simple and plausible,until at last it turns out to be easier to abandon it wholly andlook at the matter in a totally different way.

The first set of facts to be adduced against the common senseview of desire are those studied by psycho-analysis. In all humanbeings, but most markedly in those suffering from hysteria andcertain forms of insanity, we find what are called "unconscious" desires, which are commonly regarded as showing self-deception.Most psycho-analysts pay little attention to the analysis ofdesire, being interested in discovering by observation what it isthat people desire, rather than in discovering what actuallyconstitutes desire. I think the strangeness of what they reportwould be greatly diminished if it were expressed in the languageof a behaviourist theory of desire, rather than in the languageof every-day beliefs. The general description of the sort ofphenomena that bear on our present question is as follows: Aperson states that his desires are so-and-so, and that it isthese desires that inspire his actions; but the outside observerperceives that his actions are such as to realize quite differentends from those which he avows, and that these different ends aresuch as he might be expected to desire. Generally they are lessvirtuous than his professed desires, and are therefore lessagreeable to profess than these are. It is accordingly supposedthat they really exist as desires for ends, but in a subconsciouspart of the mind, which the patient refuses to admit intoconsciousness for fear of having to think ill of himself. Thereare no doubt many cases to which such a supposition is applicablewithout obvious artificiality. But the deeper the Freudians delveinto the underground regions of instinct, the further they travelfrom anything resembling conscious desire, and the less possibleit becomes to believe that only positive self-deception concealsfrom us that we really wish for things which are abhorrent to ourexplicit life.

In the cases in question we have a conflict between the outsideobserver and the patient's consciousness. The whole tendency ofpsycho-analysis is to trust the outside observer rather than thetestimony of introspection. I believe this tendency to beentirely right, but to demand a re-statement of what constitutesdesire, exhibiting it as a causal law of our actions, not assomething actually existing in our minds.

But let us first get a clearer statement of the essentialcharacteristic of the phenomena.

A person, we find, states that he desires a certain end A, andthat he is acting with a view to achieving it. We observe,however, that his actions are such as are likely to achieve aquite different end B, and that B is the sort of end that oftenseems to be aimed at by animals and savages, though civilizedpeople are supposed to have discarded it. We sometimes find alsoa whole set of false beliefs, of such a kind as to persuade thepatient that his actions are really a means to A, when in factthey are a means to B. For example, we have an impulse to inflictpain upon those whom we hate; we therefore believe that they arewicked, and that punishment will reform them. This belief enablesus to act upon the impulse to inflict pain, while believing thatwe are acting upon the desire to lead sinners to repentance. Itis for this reason that the criminal law has been in all agesmore severe than it would have been if the impulse to amelioratethe criminal had been what really inspired it. It seems simple toexplain such a state of affairs as due to "self-deception," butthis explanation is often mythical. Most people, in thinkingabout punishment, have had no more need to hide their vindictiveimpulses from themselves than they have had to hide theexponential theorem. Our impulses are not patent to a casualobservation, but are only to be discovered by a scientific studyof our actions, in the course of which we must regard ourselvesas objectively as we should the motions of the planets or thechemical reactions of a new element.

The study of animals reinforces this conclusion, and is in manyways the best preparation for the analysis of desire. In animalswe are not troubled by the disturbing influence of ethicalconsiderations. In dealing with human beings, we are perpetuallydistracted by being told that such-and-such a view is gloomy orcynical or pessimistic: ages of human conceit have built up sucha vast myth as to our wisdom and virtue that any intrusion of themere scientific desire to know the facts is instantly resented bythose who cling to comfortable illusions. But no one careswhether animals are virtuous or not, and no one is under thedelusion that they are rational. Moreover, we do not expect themto be so "conscious," and are prepared to admit that theirinstincts prompt useful actions without any prevision of the endswhich they achieve. For all these reasons, there is much in theanalysis of mind which is more easily discovered by the study ofanimals than by the observation of human beings.

We all think that, by watching the behaviour of animals, we candiscover more or less what they desire. If this is the case--andI fully agree that it is--desire must be capable of beingexhibited in actions, for it is only the actions of animals thatwe can observe. They MAY have minds in which all sorts of thingstake place, but we can know nothing about their minds except bymeans of inferences from their actions; and the more suchinferences are examined, the more dubious they appear. It wouldseem, therefore, that actions alone must be the test of thedesires of animals. From this it is an easy step to theconclusion that an animal's desire is nothing but acharacteristic of a certain series of actions, namely, thosewhich would be commonly regarded as inspired by the desire inquestion. And when it has been shown that this view affords asatisfactory account of animal desires, it is not difficult tosee that the same explanation is applicable to the desires ofhuman beings.

We judge easily from the behaviour of an animal of a familiarkind whether it is hungry or thirsty, or pleased or displeased,or inquisitive or terrified. The verification of our judgment, sofar as verification is possible, must be derived from theimmediately succeeding actions of the animal. Most people wouldsay that they infer first something about the animal's state ofmind--whether it is hungry or thirsty and so on--and thencederive their expectations as to its subsequent conduct. But thisdetour through the animal's supposed mind is wholly unnecessary.We can say simply: The animal's behaviour during the last minutehas had those characteristics which distinguish what is called"hunger," and it is likely that its actions during the nextminute will be similar in this respect, unless it finds food, oris interrupted by a stronger impulse, such as fear. An animalwhich is hungry is restless, it goes to the places where food isoften to be found, it sniffs with its nose or peers with its eyesor otherwise increases the sensitiveness of its sense-organs; assoon as it is near enough to food for its sense-organs to beaffected, it goes to it with all speed and proceeds to eat; afterwhich, if the quantity of food has been sufficient, its wholedemeanour changes it may very likely lie down and go to sleep.These things and others like them are observable phenomenadistinguishing a hungry animal from one which is not hungry. Thecharacteristic mark by which we recognize a series of actionswhich display hunger is not the animal's mental state, which wecannot observe, but something in its bodily behaviour; it is thisobservable trait in the bodily behaviour that I am proposing tocall "hunger," not some possibly mythical and certainlyunknowable ingredient of the animal's mind.

Generalizing what occurs in the case of hunger, we may say thatwhat we call a desire in an animal is always displayed in a cycleof actions having certain fairly well marked characteristics.There is first a state of activity, consisting, withqualifications to be mentioned presently, of movements likely tohave a certain result; these movements, unless interrupted,continue until the result is achieved, after which there isusually a period of comparative quiescence. A cycle of actions ofthis sort has marks by which it is broadly distinguished from themotions of dead matter. The most notable of these marks are--(1)the appropriateness of the actions for the realization of acertain result; (2) the continuance of action until that resulthas been achieved. Neither of these can be pressed beyond apoint. Either may be (a) to some extent present in dead matter,and (b) to a considerable extent absent in animals, whilevegetable are intermediate, and display only a much fainter formof the behaviour which leads us to attribute desire to animals.(a) One might say rivers "desire" the sea water, roughlyspeaking, remains in restless motion until it reaches either thesea or a place from which it cannot issue without going uphill,and therefore we might say that this is what it wishes while itis flowing. We do not say so, because we can account for thebehaviour of water by the laws of physics; and if we knew moreabout animals, we might equally cease to attribute desires tothem, since we might find physical and chemical reactionssufficient to account for their behaviour. (b) Many of themovements of animals do not exhibit the characteristics of thecycles which seem to embody desire. There are first of all themovements which are "mechanical," such as slipping and falling,where ordinary physical forces operate upon the animal's bodyalmost as if it were dead matter. An animal which falls over acliff may make a number of desperate struggles while it is in theair, but its centre of gravity will move exactly as it would ifthe animal were dead. In this case, if the animal is killed atthe end of the fall, we have, at first sight, just thecharacteristics of a cycle of actions embodying desire, namely,restless movement until the ground is reached, and thenquiescence. Nevertheless, we feel no temptation to say that theanimal desired what occurred, partly because of the obviouslymechanical nature of the whole occurrence, partly because, whenan animal survives a fall, it tends not to repeat the experience.

There may be other reasons also, but of them I do not wish tospeak yet. Besides mechanical movements, there are interruptedmovements, as when a bird, on its way to eat your best peas, isfrightened away by the boy whom you are employing for thatpurpose. If interruptions are frequent and completion of cyclesrare, the characteristics by which cycles are observed may becomeso blurred as to be almost unrecognizable. The result of thesevarious considerations is that the differences between animalsand dead matter, when we confine ourselves to externalunscientific observation of integral behaviour, are a matter ofdegree and not very precise. It is for this reason that it hasalways been possible for fanciful people to maintain that evenstocks and stones have some vague kind of soul. The evidence thatanimals have souls is so very shaky that, if it is assumed to beconclusive, one might just as well go a step further and extendthe argument by analogy to all matter. Nevertheless, in spite ofvagueness and doubtful cases, the existence of cycles in thebehaviour of animals is a broad characteristic by which they areprima facie distinguished from ordinary matter; and I think it isthis characteristic which leads us to attribute desires toanimals, since it makes their behaviour resemble what we do when(as we say) we are acting from desire.

I shall adopt the following definitions for describing thebehaviour of animals:

A "behaviour-cycle" is a series of voluntary or reflex movementsof an animal, tending to cause a certain result, and continuinguntil that result is caused, unless they are interrupted bydeath, accident, or some new behaviour-cycle. (Here "accident"may be defined as the intervention of purely physical lawscausing mechanical movements.)

The "purpose" of a behaviour-cycle is the result which brings itto an end, normally by a condition of temporaryquiescence-provided there is no interruption.

An animal is said to "desire" the purpose of a behaviour cyclewhile the behaviour-cycle is in progress.

I believe these definitions to be adequate also to human purposesand desires, but for the present I am only occupied with animalsand with what can be learnt by external observation. I am veryanxious that no ideas should be attached to the words "purpose"and "desire" beyond those involved in the above definitions.

We have not so far considered what is the nature of the initialstimulus to a behaviour-cycle. Yet it is here that the usual viewof desire seems on the strongest ground. The hungry animal goeson making movements until it gets food; it seems natural,therefore, to suppose that the idea of food is present throughoutthe process, and that the thought of the end to be achieved setsthe whole process in motion. Such a view, however, is obviouslyuntenable in many cases, especially where instinct is concerned.Take, for example, reproduction and the rearing of the young.Birds mate, build a nest, lay eggs in it, sit on the eggs, feedthe young birds, and care for them until they are fully grown. Itis totally impossible to suppose that this series of actions,which constitutes one behaviour-cycle, is inspired by anyprevision of the end, at any rate the first time it isperformed.* We must suppose that the stimulus to the performanceof each act is an impulsion from behind, not an attraction fromthe future. The bird does what it does, at each stage, because ithas an impulse to that particular action, not because itperceives that the whole cycle of actions will contribute to thepreservation of the species. The same considerations apply toother instincts. A hungry animal feels restless, and is led byinstinctive impulses to perform the movements which give itnourishment; but the act of seeking food is not sufficientevidence from which to conclude that the animal has the thoughtof food in its "mind."

Coming now to human beings, and to what we know about our ownactions, it seems clear that what, with us, sets abehaviour-cycle in motion is some sensation of the sort which wecall disagreeable. Take the case of hunger: we have first anuncomfortable feeling inside, producing a disinclination to sitstill, a sensitiveness to savoury smells, and an attractiontowards any food that there may be in our neighbourhood. At anymoment during this process we may become aware that we arehungry, in the sense of saying to ourselves, "I am hungry"; butwe may have been acting with reference to food for some timebefore this moment. While we are talking or reading, we may eatin complete unconsciousness; but we perform the actions of eatingjust as we should if we were conscious, and they cease when ourhunger is appeased. What we call "consciousness" seems to be amere spectator of the process; even when it issues orders, theyare usually, like those of a wise parent, just such as would havebeen obeyed even if they had not been given. This view may seemat first exaggerated, but the more our so-called volitions andtheir causes are examined, the more it is forced upon us. Thepart played by words in all this is complicated, and a potentsource of confusions; I shall return to it later. For thepresent, I am still concerned with primitive desire, as it existsin man, but in the form in which man shows his affinity to hisanimal ancestors.

Conscious desire is made up partly of what is essential todesire, partly of beliefs as to what we want. It is important tobe clear as to the part which does not consist of beliefs.

The primitive non-cognitive element in desire seems to be a push,not a pull, an impulsion away from the actual, rather than anattraction towards the ideal. Certain sensations and other mentaloccurrences have a property which we call discomfort; these causesuch bodily movements as are likely to lead to their cessation.When the discomfort ceases, or even when it appreciablydiminishes, we have sensations possessing a property which wecall PLEASURE. Pleasurable sensations either stimulate no actionat all, or at most stimulate such action as is likely to prolongthem. I shall return shortly to the consideration of whatdiscomfort and pleasure are in themselves; for the present, it istheir connection with action and desire that concerns us.Abandoning momentarily the standpoint of behaviourism, we maypresume that hungry animals experience sensations involvingdiscomfort, and stimulating such movements as seem likely tobring them to the food which is outside the cages. When they havereached the food and eaten it, their discomfort ceases and theirsensations become pleasurable. It SEEMS, mistakenly, as if theanimals had had this situation in mind throughout, when in factthey have been continually pushed by discomfort. And when an